Robotics, and specific movements for many other applications, require the movement of some reference point to any location in an X-Y plane, whereupon some event can occur precisely at that location. Positioners are well-known for such purposes. They are almost equally well-known for their complexity and high cost. The complexity they generally involve increases with the accuracy they are intended to deliver. Modern manufacturing processes call for increasing accuracy in order to improve the reliability and repeatability of produced products--a cost saving objective. This is countered by the increased cost of the production machinery, in which the precise placement of workpieces, or of circuit components is fundamental.
In addition, to be affordable these must function rapidly. Previous devices intended for rapid accurate movements tend to be heavy in order to provide the necessary rigidity, which in turn results in increased power requirements and more expensive positive sensing and powering components. For example, a Y axis carriage, motor and control placed physically on an X axis carriage, motor and control massively increases the need for rigidity and thereby the weight and the power to move quickly. These also drive up the cost of the positioner.
It is an object of this invention to provide an X-Y positioner which is able to control the movement of a reference point anywhere in a prescribed X-Y plane, utilizing only movements in the X axis to support and position both X and Y positioning devices and controls, thereby importantly reducing the cost and weight of the system, and improving its responsiveness.